Self-feeding press for producing strip material

ABSTRACT

A press for compacting and integrating material to form a continuous strip comprising spaced parallel arrays of long narrow bars, a frame supporting the bars in each array for reciprocal movement, a feeder for supplying material to the space between the arrays of bars at one end of the press, rams for effecting relative movement of the arrays of bars toward each other to apply compacting pressure, and rams for effecting longitudinal movement of the bars in each array in a predetermined succession in one direction and for retracting all of the bars in consonance in the other direction.

[ Sept. 16, 1975 SELF-FEEDING PRESS FOR PRODUCING STRIP MATERIAL RobertA. 'Caughey, Clinton Rd., Antrim, NH. 03440 22 1 Filed: Aug. 23, 1974 21Appl. No.: 499,935

Related US. Application Data [63] Continuation of Serv No. 317,136, Dec.21, 1972,

[76] Inventor:

abandoned.

[52] US. Cl. 100/215; 100/222; 100/295; 425/338; 425/406 [51] Int. Cl.B30B 15/30 [58] Field of Search 100/144, 215, 222, 224,

[56] References Cited UNITED STATES PATENTS 3,577,304 5/1971 Guyer156/555 Primary Examiner--William A. Powell Assistant Examiner--Brian J.Leitten Attorney, Agent, or Firm-Robert T. Gammons [5 7] ABSTRACT Apress for compacting and integrating material to form a continuous stripcomprising spaced parallel arrays of long narrow bars, a framesupporting the bars in each array for reciprocal movement, a feeder forsupplying material to the space between the arrays of bars at one end ofthe press, rams for effecting relative movement of the arrays of barstoward each other to apply compacting pressure, and rams for effecting1ongitudinal movement of the bars in each array in a predeterminedsuccession in one direction and for retracting all of the bars inconsonance in the other direction.

15 Claims, 16 Drawing Figures PATENTED ms 3, 905,290

SHLU 1 [IF 5 FIGZ FIG-3 FIGBB PATENTED 5W5 3,905,290

SHEET 2 OF 5 PRESSED STRIP F|G 4 UNPRESSED MATERIAL FIG. 4-?) PISA-4FIG.4

PATENTEBSEP'I ems SHEETSUFS D C 4. u

w p w O M \o/ 0/ FIGM! FIGIO FIGB FISH

SELF -FEEDING PRESS FOR PRODUCING STRIP MATERIAL This is a continuationof application Ser. No. 317,136, filed on Dec. 21, 1972 now abandoned.

BACKGROUND OF THE INVENTION The object of this invention is to provide apress whereby pressure can be continuously applied to a substrate suchas plywood, wood particle molding compound, laminates and the like whilethe substrate is simultaneously being moved through the press.

The importance of such a press is apparent when consideration is givento the relation of time and temperature in the curing of the adhesiveused; for example, in the production of particle board, say inch thick,a pressing time of 8 to minutes may be required in the hot press inorder to allow time for the center of the strip to reach curingtemperature, it being necessary for heat to be transferred from thesurfaces of the press platens through inch of molding compound.

If, however, the molding compound could be quickly brought to presstemperature outside the press and then injected into the press in amatter of a few seconds the press time need be only one minute or lesssince, at the press temperature employed, the resin can be cured in thisshort period.

However, with conventional presses in which the molding compound isspread on a tray or caul and then injected into the open press, the timeinvolved in preparing the mat on the caul and loading and unloading thepress is so great that the molding compound must be handled at lowtemperature in order to prevent precure of the resin or binder beforepressure can be applied. Thus with an intermittent pressing operation itis imperative to use cold molding compound which, in turn, requires thatthe molding compound be raised to curing temperature in the press. Thisaccounts for long press cycles and requires large equipment to achievesubstantial production rate.

If, however, the pressing operation could be made continuous so that themat of molding compound could be laid in the throat of the presscontinuously and then moved immediately into the press such that theelapsed time between laying of the mat and application of full pressure(with simultaneous reduction to final thickness) could be accomplishedin say 10 to seconds then it would become possible to rapidly preheatthe molding compound close to curing temperature and draw it into thehigh pressure zone in a matter of seconds after preheating withoutdanger of precuring. The elapsed time between mat formation andcompletion of this finished strip would then be only the nominal curetime of the resin system which might be say one minute, since the pressplatens need to deliver very little heat to the curing mass. Thus theplaten areas required for a given throughput of material would bereduced by the ratio of press time of conventional versus a continuoussystem. This reduction can be of the order of /3 to 1/6 depending onstrip thickness. In fact, with a continuous system, using a preheatedsubstrate, very substantial thickness may be cured in a very short time.

Summary A press for compacting and integrating material while movingthrough the press comprising spaced parallel arrays of long narrow bars,means supporting the bars in each array for reciprocal movement, meansfor supplying material to the space between the arrays of bars at oneend of the press, and means for effecting longitudinal reciprocalmovement of the bars in each array in a predetermined succession in onedirection for applying compacting pressure to the material and forretraction of all of the bars in consonance in the other direction toadvance the compacted material through the press. Spaced parallelplatens support the long narrow bars side-by-side for movementlongitudinally and these platens are in turn supported for movementtoward each other to enable applying pressure to the material betweenthe bars. Antifriction means in the form of antifriction sheets orroller bearings are disposed between the confronting sides of theplatens and the bars to reduce the resistance to sliding movement of thebars relative to the platens. There are rams operably connected to oneof the platens for effecting movement toward the other to applycompacting pressure, there is a ram connected to each of the bars toenable advancing each bar independently of every other bar and controlmeans for effecting advance of the bars in a predetermined sequence andretracting the entire number of bars in consonance. At the receiving endof the press the bars at the upper side diverge to facilitate entranceof the unpressed material to the space between the bars. To provide forheating or cooling to effect curing the bars contain passageslongitudinally thereof to which a heating or cooling medium is supplied.For particulate material which has very low integrity a carrier web suchas paper, a screen or cloth is supported in engagement with theconfronting faces of the bars in the two arrays with portions at theentrance end of the press moving toward the entrance to the spacebetween the bars for entraining the uncompressed material and drawing itinto the press.

The invention will now be described in greater detail with reference tothe accompanying drawings wherein:

FIG. 1 is a plan view of the press;

FIG. 2 is a vertical section taken longitudinally of the press;

FIG. 3 is an elevation at one end of the press;

FIG. 3a is a fragmentary elevation showing a gravitytype feeder;

FIG. 3b is a fragmentary elevation showing a conveyor-type feeder;

FIG. 4 diagrammatically illustrates the sequence of operation of thebars and the travel cycle;

FIG. 5 is a schematic of the electrical control for the press;

FIG. 6 is a schematic of the hydraulic control for the press;

FIG. 7 is a longitudinal section showing the use of conveyor members forinducting particular material into the press;

FIG. 8 diagrammatically illustrates an arrangement of bars for formingan angle section;

FIG. 9 diagrammatically illustrates an arrangement of bars for forming aU-shaped section;

FIG. 10 diagrammatically illustrates an arrangement of bars for formingan eye section;

FIG. 11 diagrammatically illustrates an arrangement of bars for forminga solid rod;

FIG. 12 diagrammatically illustrates an arrangement of bars for forminga hollow cylinder;

FIG. 13 is a transverse section of the press mounted within a frame forlongitudinal reciprocal movement; and

FIG. 14 diagrammatically shows means for effecting reciprocal movementof the press.

Referring to the drawings (FIGS. 1, 2 and 3), the press comprises abottom platen along the opposite longitudinal edges of which there aresecured at longitudinally spaced intervals posts l212 on which there ismounted an upper platen 14 corresponding in configuration and size tothe lower platen for movement toward and from the lower platen. Headerbars 16 mounted on the upper ends of the posts 12-12 provide for a rigidstructure and rams 18 mounted between the header bars and the platen 14provide for effecting movement of the upper platen 14 toward and fromthe lower platen l0.

Each of the platens 10 and 14 has at one end, the left end as shown inFIG. 1, an opening 20 within which there are mounted longitudinallyspaced ram cylinders 22, 24 between which there is a common ram 26, theram cylinders being operable to advance and retract the rams. Two arraysof long narrow bars 27 are mounted between the confronting faces of theplatens, there being four bars 29 in each array arranged side-byside, asshown in FIG. 3, with a space 31 therebetween for receiving material tobe compacted and integrated. Each bar 29 has a'driving lug 28 mounted toone of the rams 26 by means of which the bars are movable longitudinallyand reciprocably with respect to the platens. The bars are slidablysupported on the platens, for example, on bars 29 or by dove-tail tongueand groove connections.

To provide for free movement without expenditure of an abnormal amountof power, friction means 30 FIGS. 2 and 7 in the form of strips ofantifriction material or roller bearings are disposed between the barsand the platens.

The material which is to be compacted and integrated is introduced tothe entrance end of the press (FIG. 2) by means of a suitable dispenser33 FIG. 3A from which the material gravitates onto the lower one of theplatens at the entrance end or by means of a suitable conveyor 35 FIG.3B for advancing a mat of the uncompressed material to the open end ofthe press and to facilitate entrance the ends of the upper bars at theentrance end are inclined upwardly relative to the lower bars to providea converging entrance to the space between the bars. If sheet materialsuch as layers of veneer are to be combined they are pushed along atable provided at the entrance to the press.

The bars 29 may be cored for heating, for example, with steam'or cooled,for example with water.

Hydraulic pressure is applied to the rams to effect operation thereof bymeans of a pump VP (FIG. 6) driven by a motor M1. A hydraulic motor M2connected to the hydraulic circuit operates to turn a cam shaft which,in turn, operates to close a series of electric switches LS1 to LS4,inclusive, (FIG. 5). The electric switches when closed energizesolenoid-operated valves SVl to SV4, inclusive, which control the ramsfor moving the bars forwardly and reversely. The cam shaft is designed,as shown in FIG. 6, to supply pressure to rams l and 7, then to rams 2and 8, then to rams 3 and 5 and finally to rams 4 and 6 to move theaforesaid bars forwardly in that sequence and upon reversal of thevalves to supply pressure to the rams of all of the bars at the sametime to withdraw all of the bars in consonance.

The operating principle of the press depends on a division of thefriction between the substrate, that is, the material being compactedand integrated and the moving bars. In the condition showndiagrammatically in FIG. 4 all of the moving bars are in their extremeleft position and bearing substantially equal on the substrate. It isreasonable to assume that the coefficient of friction between thesubstrate and any one of the moving bars will be substantially the sameas with any other bar. Thus if sufficient pressure is applied to drivethe bar 1 to the right (FIGS. 1 and 2) while the other seven bars arerestrained and assuming that the internal shear strength of thesubstrate is sufficient to resist shearing force due to the frictionbetween the substrate and the surface of the moving bar then the barwill slide over the substrate while the substrate remains in itsoriginal position because of the relatively large amount of frictionderived from contact with the other seven bars.

If now additional bars 2, 3 and 4, etc. are advanced one at a time(FIGS. 4-2, 4-4, 4-5) to the same forward limit as bar 1 then when alleight bars shall have been advanced to the right, the substrate willstill be in its original position but the bars will all have traversedover it to the right by the same increment X of travel. If at this pointforce is simultaneously applied to all eight bars in the reversedirection they will all move simultaneously to the left with respect tothe platens, carrying with them the substrate which will then have beenadvanced to the left by one increment of bar travel. Repetition of thiscycle will thus cause the substrate to move from right to left throughthe press.

By providing one or both sets of bars at the entrance end of the presswith divergent or curved portions so as to form an entrance nip thesubstrate may be compressed in volume as it enters the space between thebars. The configuration of the entrance is designed to conform to theproperties and desired deformation of the substrate. For example, inprocessing veneers, as in plywood manufacture, the reduction at theentrance to the space between the bars would be slight. However, in theproduction of particle board where thickness reduction may be 3 or 4 tol the divergent relation of the bars to each other at the entrance wouldhave to be substantial.

In the compaction and integration of granular material where theintegrity of the mat is very low in the uncompressed condition it isusually necessary to provide a carrier web referred to which may be ofpaper, screen or cloth to support the material until it shall have beencompressed to a degree sufficient to provide an internal shear strengthgreat enough to resist the shear action of the movement of theindividual bars. Such a web is shown in FIG. 7 in the form of an endlessbelt 38 entrained about sheaves 40.

To compensate for variation in density or thickness in the substrate,the press platens may be hydraulically or otherwise loaded to permitsome vertical movement while maintaining controlled pressure on thesubstrate.

The bars as disclosed herein are arranged in spaced parallel arrays inwhich the bars in each array are situated in a common plane so that thestrip produced is flat and has spaced parallel surfaces. It is withinthe scope of the invention to arrange the bars in the arrays at anglesto each other to produce angle members (FIG. 8); channel members (FIG.9) eye members (FIG. and arcuately or around a common axis to producesolid rods (FIG. 11) and hollow cylinders or sections (FIG. 12).

As thus far described while the strip being formed is continuous thereciprocation of the bars makes delivery of the strip intermittent. Toprovide for continuous delivery of the strip the press, as indicated inFIG. 13, is reciprocably mounted in a supporting frame comprising alower frame member 40 and an upper frame member 42 rigidly joined toeach other in vertically spaced relation by shouldered tie rods 44, theframe members collectively defining a tunnel within which the press isslidingly mounted for reciprocal movement within roller bearings 48 atthe top and bottom and roller bearings 50 at the sides. Reciprocalmovement of the press can be provided by a cylinder and piston assemblyS4 and linkage 56 connecting the piston to the press or a cam-actuatedlinkage and since the press is reciprocated the source of supply, bymeans of which the material to be compressed is deposited on the pressplaten, is provided with a suitable flexible mounting to enable it tofollow the reciprocable movement of the press. The reciprocal movementof the press to provide for continuous delivery is synchronized with themovement of the bars so that on the forward movement of the bars theentire press is moved toward the left and on the rearward movement ofthe bars the entire press is moved toward the right. The stroke of thereciprocal movement of the press would, of course, correspond to thestroke of the bars.

The continuous movement of the strip material enables secondaryoperations as it is delivered from the press such as laminating, orfinishing which is desirably carried out in the same production line.

It should be understood that the present disclosure is for the purposeof illustration only and that this invention includes all modificationsand equivalents falling within the scope of the appended claims.

I claim:

1. A press for compacting and integrating material to form continuousflat sheets comprising spaced parallel arrays of long narrow bars, meanssupporting the arrays for relative movement toward each other and forsupporting the bars in each array for reciprocal movement, means forsupplying the material to the space between the arrays of bars at oneend of the press, means for applying a predetermined constant uniformpressure perpendicular to the arrays of bars so as to apply a uniformlyconstant pressure transversely of the material introduced between thebars, means for advancing the bars individually in a predeterminedsequence in sliding compressive engagement with the material in thedirection opposite to the direction of movement of the material into thepress, means for retracting all of the bars in consonance to withdrawthe strip from the press and means for urging the bars in the arrays ofbars toward each other through reciprocal movement of the bars.

2. Apparatus according to claim 1, wherein said reciprocal movement ofthe bars is a fractional part of the length of the bars and there ismeans for effecting repeated reciprocation of the bars to continuouslydraw material into the press at one end and discharge the strip from theother end.

3. A press for compacting and integrating material to form a continuousstrip comprising spaced parallel arrays of long narrow bars, meanssupporting the bars in each array for reciprocal movement, means forsupplying the material to the space between the arrays of bars at oneend of the press, and means for effecting longitudinal movement of thebars in sliding compressive engagement with the material in apredetermined succession in which less than all of the bars are advancedat any one time in said direction and for retracting all of the bars inconsonance in the other direction.

4. A press according to claim 3, means for advancing the bars in adirection opposite to the direction of movement of the material into thepress and retracting the bars in a direction to withdraw the formedstrip from the press.

5. Apparatus according to claim 3, comprising a supporting frame, meanssupporting the press in the supporting frame for longitudinal reciprocalmovement, and means for effecting reciprocal movement of the press insuch relation to the movement of the bars that the press is moving in adirection opposite to that of the bars.

6. Apparatus according to claim 3, comprising a supporting frame, meanssupporting the press in the supporting frame for longitudinal reciprocalmovement, a reciprocable motor, means connecting the motor to the press,and means operable to initiate operation of the motor in timed relationto the reciprocation of the bars such that movement of the bars in thedirection of application of pressure to the material is accompanied bymovement of the press in the opposite direction.

7. A press for compacting and integrating material to form a continuousstrip comprising spaced parallel platens, long narrow bars arranged sideby side at the confronting sides of the platens defining a space ofpredetermined width therebetween, means for supplying the material tothe space between the bars at one end of the press, means for advancingthe bars independently of the platens in a predetermined sequence insliding engagement with the material in which less than the entirenumber of bars are advanced at one time until all of the bars areadvanced and means for retracting the entire number of bars inconsonance.

8. A press according to claim 7, means for advancing the bars in adirection opposite to the direction of movement of the material into thepress and retracting the bars in a direction to withdraw the compactedstrip from the press.

9. A press for compacting and integrating material to form a continuousstructure of a predetermined cross section comprising spaced parallelplatens, means supporting the platens for relative movement toward eachother, long narrow bars mounted at the confronting sides of the platensfor reciprocal movement longitudinally thereof, the bars in each arraybeing movable individually relative to each other, means for supplyingmaterial to the space between the bars at one end of the press, meansfor advancing the bars individually in a predetermined sequence insliding compressive engagement with the material until all of the barsare advanced and means for retracting all of the bars a correspondingamount in consonance while still in compressive engagement with theformed structure to withdraw the structure from the press as it isformed.

10. A press for compacting and integrating material to form a continuousstrip comprising spaced parallel platens, means for supporting theplatens for relative movement toward each other, means for effectingmovement of the platens toward each other, antifriction means at theconfronting sides of the platens,

long narrow bars supported against the anti-friction means inconfronting relation to each other with a predetermined spacetherebetween, for reciprocal movement longitudinally of the platens,means for supplying material to a space between the arrays of platens,means for advancing the bars individually in a predetermined sequence inwhich less than the entire number of bars are moved at one time, insliding compressive engagement with the material and means forretracting all of the bars in consonance while still in compressiveengagement with the material progressively to with draw the strip fromthe press as it is formed.

11. A press according to claim 10, wherein the antifriction meanscomprise lengths of antifriction material secured to the confrontingfaces of the platens.

12. A press according to claim 10, wherein the antifriction meanscomprise roller bearings supported against the confronting sides of theplatens.

13. Apparatus for continuously producing continuous strip comprisingspaced parallel arrays of longitudinal extending narrow bars arrangedside by side transversely of the apparatus between which is adapted tobe introduced material to be formed into continuous strip, means forapplying a predetermined continuous pres sure perpendicular to thearrays of bars such that the material of which the strip is comprised issubjected to a constant continuous pressure as it progresses through theapparatus, means for successively advancing the bars in slidingengagement with the material longitudinal of the apparatus until all ofthe bars have been moved so that there is an insufficient frictionalforce developed by movement of any bar to displace the material in thedirection of advance of the bars and means for thereafter withdrawingall of the bars in unison.

14. In an apparatus for continuously producing continuous strip, a pressassembly comprising a rigid frame, spaced parallel arrays oflongitudinal extending narrow bars arranged side by side transversely ofthe frame between which is adapted to be introduced material to beformed into a strip, means for applying a predetermined continuousuniform pressure perpendicular to the arrays of the bars such that theentire width of the material of which the strip is comprised issubjected to a constant uniform continuous pressure transversely thereofas it progresses through the press, means connected to an end of eachbar for moving the bar and means operating to effect reciprocal movementof the bars forwardly a predetermined distance longitudinally of thepress opposite to the progress of the material through the press andrearwardly to effect discharge of the formed strip said means effectingsequential movement of individual bars representing less than half ofthe total surface area forwardly until all of the bars are advanced andthereafter rearwardly in unison, means supporting the frame mounting thebars for reciprocation and means for effecting reciprocation of the barsand the frame in opposite directions such that forward movement of thebars is accompanied by rearward movement of the press assembly.

15. A press for compacting and integrating material to form a continuousstrip comprising spaced parallel platens, means supporting the platensfor relative movement toward each other, rams arranged to effect suchrelative movement, long narrow bars arranged side-by-side on theconfronting faces of the platens for reciprocal movement longitudinallythereof, means for supplying material to the space between the bars, aram connected to each bar for effecting movement thereof independentlyof every other bar, and control means operable to effect advancemovement of the bars in a predetermined sequence and for retracting allof the bars in consonance.

1. A press for compacting and integrating material to form continuousflat sheets comprising spaced parallel arrays of long narrow bars, meanssupporting the arrays for relative movement toward each other and forsupporting the bars in each array for reciprocal movement, means forsupplying the material to the space between the arrays of bars at oneend of the press, means for applying a predetermined constant uniformpressure perpendicular to the arrays of bars so as to apply a uniformlyconstant pressure transversely of the material introduced between thebars, means for advancing the bars individually in a predeterminedsequence in sliding compressive engagement with the material in thedirection opposite to the direction of movement of the material into thepress, means for retracting all of the bars in consonance to withdrawthe strip from the press and means for urging the bars in the arrays ofbars toward each other through reciprocal movement of the bars. 2.Apparatus according to claim 1, wherein said reciprocal movement of thebars is a fractional part of the length of the bars and there is meansfor effecting repeated reciprocation of the bars to continuously drawmaterial into the press at one end and discharge the strip from theother end.
 3. A press for compacting and integrating material to form acontinuous strip comprising spaced parallel arrays of long narrow bars,means supporting the bars in each array for reciprocal movement, meansfor supplying the material to the space between the arrays of bars atone end of the press, and means for effecting longitudinal movement ofthe bars in sliding compressive engagement with the material in apredetermined succession in which less than all of the bars are advancedat any one time in said direction and for retracting all of the bars inconsonance in the other direction.
 4. A press according to claim 3,means for advancing the bars in a direction opposite to the direction ofmovement of the material into the press and retracting the bars in adirection to withdraw the formed strip from the press.
 5. Apparatusaccording to claim 3, comprising a supporting frame, means supportingthe press in the supporting frame for longitudinal reciprocal movement,and means for effecting reciprocal movement of the press in suchrelation to the movement of the bars that the press is moving in adirection opposite to that of the bars.
 6. Apparatus according to claim3, comprising a supporting frame, means supporting the press in thesupporting frame for longitudinal reciprocal movement, a reciprocablemotor, means connecting the motor to the press, and means operable toinitiate operation of the motor in timed relation to the reciprocationof the bars such that movement of the bars in the direction ofapplication of pressure to the material is accompanied by movement ofthe press in the opposite direction.
 7. A press for compacting andintegrating material to form a continuous strip comprising spacedparallel platens, long narrow bars arranged side by side at theconfronting sides of the platens defining a space of predetermined widththerebetween, means for supplying the material to the space between thebars at one end of the press, means for advancing the bars independentlyof the platens in a predetermined sequence in sliding engagement withthe material in which less than the entire number of bars are advancedat one time until all of the bars are advanced and means for retractingthe entire Number of bars in consonance.
 8. A press according to claim7, means for advancing the bars in a direction opposite to the directionof movement of the material into the press and retracting the bars in adirection to withdraw the compacted strip from the press.
 9. A press forcompacting and integrating material to form a continuous structure of apredetermined cross section comprising spaced parallel platens, meanssupporting the platens for relative movement toward each other, longnarrow bars mounted at the confronting sides of the platens forreciprocal movement longitudinally thereof, the bars in each array beingmovable individually relative to each other, means for supplyingmaterial to the space between the bars at one end of the press, meansfor advancing the bars individually in a predetermined sequence insliding compressive engagement with the material until all of the barsare advanced and means for retracting all of the bars a correspondingamount in consonance while still in compressive engagement with theformed structure to withdraw the structure from the press as it isformed.
 10. A press for compacting and integrating material to form acontinuous strip comprising spaced parallel platens, means forsupporting the platens for relative movement toward each other, meansfor effecting movement of the platens toward each other, anti-frictionmeans at the confronting sides of the platens, long narrow barssupported against the anti-friction means in confronting relation toeach other with a predetermined space therebetween, for reciprocalmovement longitudinally of the platens, means for supplying material toa space between the arrays of platens, means for advancing the barsindividually in a predetermined sequence in which less than the entirenumber of bars are moved at one time, in sliding compressive engagementwith the material and means for retracting all of the bars in consonancewhile still in compressive engagement with the material progressively towithdraw the strip from the press as it is formed.
 11. A press accordingto claim 10, wherein the anti-friction means comprise lengths ofantifriction material secured to the confronting faces of the platens.12. A press according to claim 10, wherein the anti-friction meanscomprise roller bearings supported against the confronting sides of theplatens.
 13. Apparatus for continuously producing continuous stripcomprising spaced parallel arrays of longitudinal extending narrow barsarranged side by side transversely of the apparatus between which isadapted to be introduced material to be formed into continuous strip,means for applying a predetermined continuous pressure perpendicular tothe arrays of bars such that the material of which the strip iscomprised is subjected to a constant continuous pressure as itprogresses through the apparatus, means for successively advancing thebars in sliding engagement with the material longitudinal of theapparatus until all of the bars have been moved so that there is aninsufficient frictional force developed by movement of any bar todisplace the material in the direction of advance of the bars and meansfor thereafter withdrawing all of the bars in unison.
 14. In anapparatus for continuously producing continuous strip, a press assemblycomprising a rigid frame, spaced parallel arrays of longitudinalextending narrow bars arranged side by side transversely of the framebetween which is adapted to be introduced material to be formed into astrip, means for applying a predetermined continuous uniform pressureperpendicular to the arrays of the bars such that the entire width ofthe material of which the strip is comprised is subjected to a constantuniform continuous pressure transversely thereof as it progressesthrough the press, means connected to an end of each bar for moving thebar and means operating to effect reciprocal movement of the barsforwardly a predetermined distance longitudinally of the press oppositeto the progress of the mAterial through the press and rearwardly toeffect discharge of the formed strip said means effecting sequentialmovement of individual bars representing less than half of the totalsurface area forwardly until all of the bars are advanced and thereafterrearwardly in unison, means supporting the frame mounting the bars forreciprocation and means for effecting reciprocation of the bars and theframe in opposite directions such that forward movement of the bars isaccompanied by rearward movement of the press assembly.
 15. A press forcompacting and integrating material to form a continuous stripcomprising spaced parallel platens, means supporting the platens forrelative movement toward each other, rams arranged to effect suchrelative movement, long narrow bars arranged side-by-side on theconfronting faces of the platens for reciprocal movement longitudinallythereof, means for supplying material to the space between the bars, aram connected to each bar for effecting movement thereof independentlyof every other bar, and control means operable to effect advancemovement of the bars in a predetermined sequence and for retracting allof the bars in consonance.